1. Field of the Invention
The present invention relates to a reel hub for winding a tape, and particularly, to a leader block for fixing a beginning of the tape to the reel hub, and a reel using the same.
2. Description of the Related Art
As a method of fixing a beginning of a tape to a reel, there is a method with which a leader pin 22 provided at a beginning of a tape 26 is engaged to a hook part 21 of a leader block 20 as shown in FIGS. 7A and 7B, and the leader block 20 is inserted into a slot 25 formed in a reel hub 24 as shown in FIG. 8. With this method, the leader block 20 forms a part of a barrel of the reel.
A magnetic tape recording device has been improved to realize an increase in recording density, an extension of the length of the tape, and an increase in running velocity of the tape, for the purpose of implementation of higher-capacity recording and high-speed reading/writing. If those features described above are achieved, the length of the tape can be extended, and the reel can rotate at higher speed. When the extension of the length of the tape is achieved, the diameter of the reel with the total content of the wound tape is intended to be sustained by thinning the thickness of the tape.
When the length of the tape is extended, the number of windings of the tape on the reel increases, and a tape 26 is wound harder on a reel hub 24 of the reel, thus a leader block 20 is pressed in a radial direction of the reel hub 24 by the wound tape 26. One side of a hook part 21 of the leader block 20 is opened to engage with a leader pin 22. As shown in FIGS. 7A and 7B, when the leader block 20 is pressed in the radial direction of the reel hub 24, open side of the hook part 21 is pushed into a slot 25 of the reel hub 24 deeply, and a level difference 27 is generated at a boundary of the leader block 20 and the reel hub 24.
The level difference 27 becomes a cause of a non-uniform winding 28 of the tape particularly when the tape thickness is being thinner, and also, the non-uniform winding 28 of the tape causes a non-uniformity of the tape running velocity. Further, there is a case when the non-uniform winding 28 of the tape due to the level difference 27 attributes to an excessive force to be applied to the tape 26 for damaging a recording surface of the tape 26, and in such a case, causes a reading/writing error of the high-density recorded data. Also, the non-uniform winding 28 of the tape is possible to cause the non-uniformity of the tape running velocity, and the non-uniformity of the tape running velocity can also cause a reading/writing error of the high-density recorded data.
As a technique related to solving the problems described above, a recording tape cartridge is disclosed in Japanese Unexamined Patent Publication 2003-132652 (Patent document 1).
However, different from the system shown in FIGS. 7A and 7B, Patent document 1discloses a configuration in which the leader block is integrally attached to a beginning of the tape, and when the tape is wound by the reel of the tape cartridge (not shown), the leader block is positioned at an end portion of the tape being wound, and accommodated in the tape cartridge. Therefore, the tape cartridge accommodating the reel around which the tape is wound is required to have a space for accommodating the leader block in addition to a space for accommodating the reel, and it makes it difficult to downsize the tape cartridge.
Also, Patent document 1 discloses a configuration in which a drawing pin is inserted in an operational hole of the leader block which has been pulled out of the tape cartridge, the leader block is carried to a position of a targeted reel hub by pulling the drawing pin, and the leader block is fitted in an intrusive part formed along a circumferential direction of the reel hub. Therefore, the reel cannot be rotated before the drawing pin is pulled out of the operational hole of the leader block, and there is a limit on shortening the time from when the tape is loaded till when the data is written/read.
Further, in Patent document 1, a curved surface formed on a peripheral of the leader block occupies a large portion of a take-up surface of the reel hub on which the tape is wound, so a highly precise processing technique is required when processing the curved surface of the leader block by being positioned to form the same circumference surface as the surface of the reel hub on which the tape is wound. To this processing, a processing accuracy of the intrusive part of the reel hub is also related, and proficiency is required to process the leader block.